public class Example4_19 {
  public static void main(String args[]){
    Student2 zhang=new Student2();
    Student2 geng=new Student2();
    zhang.setAge(23);
    System.out.println("zhang的年龄："+zhang.getAge());
    geng.setAge(25);
    System.out.println("geng的年龄："+geng.getAge());
  }
}
